Create the mirror database by restoring with NORECOVERY a recent full database backup of the principal database. Make sure that the principal database was already using the full recovery model when the backup was taken. The mirror database must have the same name as the principal database, and they cannot be renamed during a database mirroring session.

Important:

You must restore all of the log backups done since the full database backup. Before you can start mirroring on the partners, you should create a current log backup on the original database and restore it to the future mirror database.